Final Version
In a Nutshell
The final version is the completed, ready-to-use version of the work after all revisions. In theory: the final file. In practice: often a final that isn't final.
What It Really Means
"Final version" is one of the least reliable expressions in agencies. Because the file called "final" sometimes gets reopened a few hours later with "one tiny change."
For a piece of work to truly be final, it's not enough for the agency to finish it. The client must actually make a decision.
The "there's just one more thing" that comes after the final file is sent is a classic of agency culture.
In agency life, "final version" often doesn't mean the work is done; it means everyone is trying to act like it is.